RHSA-2005:805 - Security Advisory

Topic

An updated pam package that fixes a security weakness is now available for
Red Hat Enterprise Linux 4.

This update has been rated as having low security impact by the Red Hat
Security Response Team.

Description

PAM (Pluggable Authentication Modules) is a system security tool that
allows system administrators to set an authentication policy without
having to recompile programs that handle authentication.

A bug was found in the way PAM's unix_chkpwd helper program validates user
passwords when SELinux is enabled. Under normal circumstances, it is not
possible for a local non-root user to verify the password of another local
user with the unix_chkpwd command. A patch applied that adds SELinux
functionality makes it possible for a local user to use brute force
password guessing techniques against other local user accounts. The Common
Vulnerabilities and Exposures project has assigned the name CVE-2005-2977 to
this issue.

All users of pam should upgrade to this updated package, which contains
backported patches to correct these issues.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via Red Hat Network. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc

Fixes

• BZ - 168181 - CVE-2005-2977 unix_chkpwd helper doesn't verify requesting user if SELinux is enabled

CVEs

• CVE-2005-2977

References

(none)